As Business Insider reports, New York City Comptroller Scott Stringer, Illinois State Treasurer Michael Frerichs, Rhode Island State Treasurer Seth Magaziner, and Pennsylvania Treasurer Joe Torsella are joining forces to pile the pressure on Zuckerberg, holding over a billion dollars between them.

They have put their names to a proposal, originally filed by activist investor Trillium Asset Management, demanding that Facebook appoint an independent chairman above Zuckerberg

"We need Facebook's insular boardroom to make a serious commitment to addressing real risks - reputational, regulatory, and the risk to our democracy - that impact the company," New York City Comptroller Stringer said in a statement.

"An independent board chair is essential to moving Facebook forward from this mess, and to reestablish trust with Americans and investors alike."

Rhode Island's Magaziner added:

"Without an independent board chair, the board's oversight of the company remains inadequate as evidenced by the recent mishandling of several controversies. Having an independent board chair... is in the best long-term interest of Facebook shareholders."